First thing I would do is go to Control Panel\Programs. Uninstall all the crap. They'll sometimes have trial software installed, like a 30 day trial of Office. Delete all the shit that isn't Windows related that you don't want.
I'd probably toss Norton 360 in the trash. It's a piece of shit, a huge resource hog, and usually causes more problems than it prevents. There's a reason they give it out for free in situations like this.
Then, go to
http://ninite.com/. Select everything you need to get started. I would suggest the following:
Chrome
VLC
Flash
Java
Gimp (Free photoshop clone for image editing)
OpenOffice (Free M$ Office clone if needed)
Adobe Reader
Avast
Malwarebytes
ImgBurn
WinRAR
That will give you a great start.
Then I'd really recommend upgrading Malwarebytes to the Pro version($24.95). It's a great investment and will keep 99.9999% of spyware/malware/trojan/etc off the machine. It's what I call "Grandma proofing". In my opinion, that's a better solution than paying for a virus scanner.
I don't really feel that Ad-Aware is necessary these days, with the built-in features present in today's browsers and virus/malware protection.